[mod.computers.vax] physical address space on uVAX-II

RAY@SRI-KL.ARPA (01/27/86)

The Q-Bus can only map 4 meg of memory at one time. The uVAX-II uses
a separate bus, not the Q-Bus, for memory ( I believe the memory boards
get there power from the q-bus, however). Thus, you have a very similar
situation to the 78x class machines and their unibus dma transfers -
the actual memory on the machine is greater then the unibus's memory
mapping space.  

Ray
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